GENERAL VIEWS. 
193 
such circumstances as to prove that the elevation of considerable tracts of 
land above the sea in those parts (near Preston, in Cheshire, and on 
the Snowdon range) has happened since the creation of the species of 
Testacea now living on the shores. Evidence is not wanting on the 
east coast of Scotland and England, and on the east coast of Ireland, 
to prove a similar variation of the level of land and sea, (independent 
of cataclysmal accidents,) and perhaps, eventually, it may appear certain 
that the elevating process, if now ended, was continued under a great 
part of the British Islands till a late geological period. If this should 
be admitted, the extraordinary phenomena of the dispersion of the 
Cumbrian rocks to the east will still require the operation of great 
and violent oceanic currents excited by sudden subterranean move- 
ments, but the dynamical difficulties of the problem will be so much 
reduced, as perhaps to bring it within the scope of an inquiry into 
the possible extent of watery currents producible by displacements of 
the crust of the globe, and thus to permit on good grounds the union 
of sudden dislocations, gradual changes of level, and distant cataclysms, 
in one point of view, as necessary results of the slowly changing tem- 
perature of the globe. 
